A mobile lawn-mowing robot can navigate about an environment to mow a confined area in that environment. The robot can determine its location within the environment by detecting beacons within the environment. The beacons can be passive beacons that reflect signals emitted by the robot or active beacons that emit signals detected by the robot. The robot can use these signals from the beacons to restrict its movement to a confined area within the environment and/or to enable systematic coverage of the lawn area.